JP4736338B2 - Diamond single crystal substrate - Google Patents
Diamond single crystal substrate Download PDFInfo
- Publication number
- JP4736338B2 JP4736338B2 JP2004085930A JP2004085930A JP4736338B2 JP 4736338 B2 JP4736338 B2 JP 4736338B2 JP 2004085930 A JP2004085930 A JP 2004085930A JP 2004085930 A JP2004085930 A JP 2004085930A JP 4736338 B2 JP4736338 B2 JP 4736338B2
- Authority
- JP
- Japan
- Prior art keywords
- region
- single crystal
- diamond
- raman
- growth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000758 substrate Substances 0.000 title claims description 95
- 239000013078 crystal Substances 0.000 title claims description 91
- 239000010432 diamond Substances 0.000 title claims description 78
- 229910003460 diamond Inorganic materials 0.000 title claims description 77
- 238000001069 Raman spectroscopy Methods 0.000 claims description 68
- 230000005284 excitation Effects 0.000 claims description 9
- 238000007740 vapor deposition Methods 0.000 claims 1
- 239000010410 layer Substances 0.000 description 28
- 238000005259 measurement Methods 0.000 description 21
- 238000001947 vapour-phase growth Methods 0.000 description 18
- 238000005336 cracking Methods 0.000 description 16
- 238000005530 etching Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 14
- 239000004065 semiconductor Substances 0.000 description 11
- 239000007789 gas Substances 0.000 description 9
- 238000001237 Raman spectrum Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 7
- 239000010408 film Substances 0.000 description 5
- 238000001020 plasma etching Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 238000003841 Raman measurement Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 238000004441 surface measurement Methods 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- 239000012808 vapor phase Substances 0.000 description 2
- 238000001530 Raman microscopy Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000000411 transmission spectrum Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 238000000927 vapour-phase epitaxy Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/02—Epitaxial-layer growth
- C30B25/18—Epitaxial-layer growth characterised by the substrate
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/02—Elements
- C30B29/04—Diamond
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Carbon And Carbon Compounds (AREA)
Description
本発明はダイヤモンド単結晶基板に関し、特に半導体材料、電子部品、光学部品などに用いられる大型かつ高品質なダイヤモンド単結晶基板に関するものである。 The present invention relates to a diamond single crystal substrate, and more particularly to a large and high quality diamond single crystal substrate used for semiconductor materials, electronic components, optical components and the like.
ダイヤモンドは高熱伝導率、高い電子・正孔移動度、高い絶縁破壊電界強度、低誘電損失、そして広いバンドギャップといった、半導体材料として他に類を見ない、優れた特性を数多く備えている。特に近年では、広いバンドギャップを活かした紫外発光素子や、優れた高周波特性を持つ電界効果トランジスタなどが開発されつつある。さらに、紫外から赤外領域にわたり透明であることから、光学部品材料としても有望である。 Diamond has many unique properties that are unparalleled as a semiconductor material, such as high thermal conductivity, high electron / hole mobility, high breakdown field strength, low dielectric loss, and wide band gap. In particular, in recent years, ultraviolet light emitting elements utilizing a wide band gap and field effect transistors having excellent high frequency characteristics are being developed. Furthermore, since it is transparent from the ultraviolet region to the infrared region, it is also promising as an optical component material.
ダイヤモンドを半導体として利用するためには、他の半導体材料と同様に大型かつ高品質な単結晶基板が必要である。現在、ダイヤモンド単結晶は主として高温高圧合成法により工業的に得られている。これは天然産単結晶と比較して結晶性に優れるが、１０ｍｍ径以上の大型化は困難であり、特殊な成長条件を用いない限り結晶中には不純物として窒素が含まれる。窒素含有の基板はそのままでは半導体単結晶としての利用を困難にするだけではなく、窒素の固有吸収のため紫外光用の窓材としても不十分となる。そこで、これを気相成長の種基板として用いてホモエピタキシャル成長させ、大型かつ高純度の単結晶基板を得る試みが進んでいる（例えば、特許文献１、２）。
高圧合成ダイヤモンド単結晶種基板上にダイヤモンド単結晶をホモエピタキシャル成長させると、気相成長層に残留応力が蓄積される現象が確認されている（例えば特許文献２）。気相成長により単結晶厚膜を形成して、ダイヤモンド単結晶基板を得る場合には、応力の蓄積により基板が割れる問題がある。基板の大型化（大面積化、厚膜化）に伴い割れる確率は増大するため、特許文献１に記載のような、実質的に相互に同じ結晶方位を持つ、複数の高圧相物質を配置して気相成長の核となる基板を形成し、その上に単結晶を気相成長法で成長させ、一体となった大型単結晶を得る方法を用いたとしても、問題は解決しない。さらに、特許文献２に示される、厚みが１００μｍ以下の種基板からダイヤモンド単結晶を気相成長しても厚膜成長時の問題は本質的に解決しない。
It has been confirmed that when a diamond single crystal is homoepitaxially grown on a high-pressure synthetic diamond single crystal seed substrate, residual stress is accumulated in a vapor phase growth layer (for example, Patent Document 2). When a single crystal thick film is formed by vapor phase growth to obtain a diamond single crystal substrate, there is a problem that the substrate breaks due to accumulation of stress. Since the probability of cracking increases as the substrate becomes larger (larger area, thicker), a plurality of high-pressure phase substances having substantially the same crystal orientation as described in
本発明は、前記課題を克服すべくなされたもので、半導体材料、電子部品、光学部品などに用いられる、大型かつ高品質なダイヤモンド単結晶基板を提供することを目的とする。 The present invention has been made to overcome the above-described problems, and an object of the present invention is to provide a large and high-quality diamond single crystal substrate used for semiconductor materials, electronic components, optical components and the like.
前記課題を解決するため、本発明は次の（１）〜（３）の態様を有する。
（１）気相成長法により得られたダイヤモンド単結晶基板であって、励起光の集光スポット径が２μｍの顕微ラマン分光法で測定した、ダイヤモンド単結晶基板表面のダイヤモンド固有ラマンシフトが、表面の０．１％以上１０％以下の領域（領域Ａ）では、歪みのないダイヤモンドの標準ラマンシフト量から＋０．５ｃｍ−１以上＋３．０ｃｍ−１以下のシフト量であり、表面の領域Ａ以外の領域（領域Ｂ）では、歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上＋０．５ｃｍ−１未満のシフト量であることを特徴とする、ダイヤモンド単結晶基板。
（２）前記、領域Ａのダイヤモンド固有ラマンピークの半値全幅が２．０ｃｍ−１以上３．５ｃｍ−１以下であり、領域Ｂのダイヤモンド固有ラマンピークの半値全幅が１．６ｃｍ−１以上２．５ｃｍ−１以下であることを特徴とする、前記（１）に記載のダイヤモンド単結晶基板。
In order to solve the above problems, the present invention has the following aspects (1) to ( 3 ).
(1) A diamond single crystal substrate obtained by vapor phase epitaxy, and the diamond intrinsic Raman shift of the surface of the diamond single crystal substrate measured by microscopic Raman spectroscopy with a focused spot diameter of excitation light of 2 μm is In the region of 0.1% or more and 10 % or less (region A), the shift amount is +0.5 cm −1 or more and +3.0 cm −1 or less from the standard Raman shift amount of undistorted diamond. of the region (region B), characterized in that it is a shift amount of less -1.0Cm -1 or + 0.5 cm -1 from the standard Raman shift of undistorted diamond, diamond single crystal substrate.
(2) The full width at half maximum of the diamond intrinsic Raman peak in region A is 2.0 cm −1 or more and 3.5 cm −1 or less, and the full width at half maximum of the diamond intrinsic Raman peak in region B is 1.6 cm −1 or more. The diamond single crystal substrate according to ( 1 ) above, which is 5 cm −1 or less.
（３）差し渡し径が１０ｍｍ以上であることを特徴とする前記（１）または（２）に記載のダイヤモンド単結晶基板。 ( 3 ) The diamond single crystal substrate as described in ( 1) or (2) above, wherein a passing diameter is 10 mm or more.
以下、上記の本発明について説明する。
本発明者らは、ダイヤモンドのホモエピタキシャル成長において応力が蓄積される現象を、２次元面分布の測定できる顕微ラマン分光装置を利用して詳細に解析した。その結果、単結晶薄膜成長表面のラマンシフト量分布では、ダイヤモンドの標準的なラマンシフト量である１３３２ｃｍ−１から前後に数ｃｍ−１ずれた領域が局所的に存在する場合があることを発見した。ラマンシフトは結晶格子の固有振動数に起因して生じることから、ダイヤモンド固有の標準シフト量からずれた領域は結晶格子が通常より狭まって、あるいは拡がって歪んだ状態なっている。そこで、さらにホモエピタキシャル成長を継続したところ、初期のラマンシフト測定で計測した歪み領域の面積が一定値以上の場合、あるいはその領域のラマンシフト量があるしきい値以上ずれていた場合、あるいはラマンピーク半値幅がある範囲を超えていた場合、単結晶の割れが頻発することを発見し、本発明を得るに至った。
Hereinafter, the present invention will be described.
The present inventors analyzed in detail the phenomenon of stress accumulation during homoepitaxial growth of diamond using a microscopic Raman spectroscope capable of measuring a two-dimensional surface distribution. As a result, the Raman shift amount distribution of the single crystal thin film growth surface, discovered that standard number cm -1 shifted region around from 1332 cm -1 Raman shift of diamond may be present locally did. Since the Raman shift is caused by the natural frequency of the crystal lattice, the region deviated from the standard shift amount inherent to the diamond is in a state where the crystal lattice is narrower than usual or expanded and distorted. Therefore, when homoepitaxial growth was further continued, if the area of the strain region measured by the initial Raman shift measurement was a certain value or more, or if the amount of Raman shift in that region was shifted by more than a certain threshold, or the Raman peak When the full width at half maximum exceeded a certain range, it was discovered that cracking of the single crystal occurred frequently, and the present invention was obtained.
すなわち、本発明のダイヤモンド単結晶基板は、気相成長法で得られたものであり、励起光の集光スポット径が２μｍの顕微ラマン分光法で測定した、ダイヤモンド単結晶基板表面のダイヤモンド固有ラマンシフトが、表面の０％より大きく２５％以下の領域（領域Ａ）では、歪みのないダイヤモンドの標準ラマンシフト量から＋０．５ｃｍ−１以上＋３．０ｃｍ−１以下のシフト量であり、表面の領域Ａ以外の領域（領域Ｂ）では、歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上＋０．５ｃｍ−１未満のシフト量であることを特徴とする。標準ラマンシフト量からのずれ量はすなわち歪みの大きさ（強さ）を示しており、その面積は歪み領域に対応することから、本発明者らは単結晶基板の割れる確率がこれらの関数で表されると考え、ラマンシフト量とその面積に関係することを実験的に明確にした。すなわち、ラマンシフト量・領域が前記範囲にあれば半導体・光学用途として利用可能な大型、高品質のダイヤモンド単結晶基板として利用できる。さらに、この基板を種基板としたホモエピタキシャル成長により、割れのない単結晶厚膜を形成することも可能になる。 That is, the diamond single crystal substrate of the present invention was obtained by a vapor phase growth method, and the diamond intrinsic Raman of the surface of the diamond single crystal substrate measured by microscopic Raman spectroscopy with a focused spot diameter of excitation light of 2 μm. shift, the 0% greater than 25% or less of the area of the surface (region a), a shift amount from the standard Raman shift + 0.5 cm -1 or + 3.0 cm -1 or less with no diamond distortion, surface in the region other than the region a (region B), characterized in that it is a shift amount of less -1.0Cm -1 or + 0.5 cm -1 from the standard Raman shift of undistorted diamond. Since the amount of deviation from the standard Raman shift amount indicates the magnitude (strength) of strain, and the area corresponds to the strain region, the present inventors have the probability that the single crystal substrate is broken by these functions. It was experimentally clarified that it is related to the amount of Raman shift and its area. That is, if the Raman shift amount / region is in the above range, it can be used as a large-sized, high-quality diamond single crystal substrate that can be used for semiconductor / optical applications. Furthermore, it becomes possible to form a single-crystal thick film without cracks by homoepitaxial growth using this substrate as a seed substrate.
前記ラマンシフトの領域Ａは表面の０％より大きく２５％以下であればよいが好ましくは１０％以下、より好ましくは３％以下が適している。一般的には少なければ少ないほどその後のホモエピタキシャル成長などで割れる確率が低下するが、詳細な研究の結果、この歪み領域Ａが少なくなりすぎても歪みが局所的に集中するために割れる確率が増大する場合もあることがわかった。すなわち、領域Ａは表面の０．１％以上存在する方が望ましい。この領域Ａのシフト量は、歪みのないダイヤモンドの標準ラマンシフト量から＋０．５ｃｍ−１以上＋３．０ｃｍ−１以下のシフト量であればよいが好ましくは＋０．５ｃｍ−１以上＋２．０ｃｍ−１以下、より好ましくは＋０．５ｃｍ−１以上＋１．０ ｃｍ−１以下が適している。領域Ａにおける最大シフト量は、結晶中の最も歪んだ領域に現れることが多く、この数値が少ないほど歪みが小さいので割れる確率が低下する。但し、先の領域Ａの面積が少なくなりすぎた時に割れる確率が増えたのと同じ理由で、結晶全体の歪みを緩和するためには少なくとも＋０．５ｃｍ−１以上のシフト量がある領域が結晶表面には必要である。すなわち、本発明では＋０．５ｃｍ−１以上のシフト量がある上記指定領域を領域Ａと定義した。 The Raman shift region A may be larger than 0% of the surface and 25% or less, preferably 10% or less, more preferably 3% or less. In general, the smaller the number, the lower the probability of cracking by subsequent homoepitaxial growth. However, as a result of detailed research, even if this strain region A becomes too small, the probability of cracking increases because the strain concentrates locally. It turns out that there is a case. That is, it is desirable that the region A exists at 0.1% or more of the surface. The shift amount of the region A may be a shift amount of +0.5 cm −1 or more and +3.0 cm −1 or less from the standard Raman shift amount of diamond without distortion, but is preferably +0.5 cm −1 or more and +2.0 cm −. 1 or less, and more preferably is suitable + 0.5 cm -1 or more +1.0 cm -1 or less. The maximum shift amount in the region A often appears in the most distorted region in the crystal, and the smaller the numerical value, the lower the strain, and the lower the probability of breaking. However, for the same reason that the probability of cracking when the area of the region A is too small is increased, a region having a shift amount of at least +0.5 cm −1 or more is required to relax the distortion of the entire crystal. It is necessary for the surface. That is, in the present invention, the designated area having a shift amount of +0.5 cm −1 or more is defined as area A.
前記ラマンシフトの領域Ｂは領域Ａの圧縮歪みの反作用として現れる部分であり、そのシフト量は歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上＋０．５ｃｍ−１未満であればよいが、好ましくは−０．５ｃｍ−１以上＋０．５ｃｍ−１未満が適している。標準シフトよりも低波数側にシフトした部分には引っ張り歪みが蓄積されており、最も低波数シフトした量が−１．０ｃｍ−１以下の場合割れる確率が増大する。逆に、この数値が０ｃｍ−１に近いほど歪みは小さく割れる確率が低下するので、この基板を種基板としたホモエピタキシャル成長により、割れのない単結晶厚膜を形成することも可能になる。 The region B of Raman shift is a portion which appears as a reaction of the compressive strain in the region A, the shift amount is less than -1.0Cm -1 or + 0.5 cm -1 from the standard Raman shift of undistorted Diamond good, preferably suitable less than -0.5Cm -1 or + 0.5 cm -1. Tensile strain is accumulated in the portion shifted to the lower wavenumber side than the standard shift, and the probability of cracking increases when the amount of the lowest wavenumber shift is −1.0 cm −1 or less. Conversely, the closer this value is to 0 cm −1 , the lower the probability that the strain will break, so that it becomes possible to form a single crystal thick film without cracks by homoepitaxial growth using this substrate as a seed substrate.
前記、領域Ａのダイヤモンド固有ラマンピークの半値全幅は２．０ｃｍ−１以上３．５ｃｍ−１以下であり、領域Ｂのそれは１．６ｃｍ−１以上２．５ｃｍ−１以下であることことが望ましい。ラマンピークの半値全幅は結晶性を反映した数値であり、一般的に小さい方が結晶として良質であることを示している。領域Ａでは圧縮歪みのため半値全幅は歪みのない結晶に比べて拡がるが、前記数値範囲内であれば割れがなく、高品質半導体として利用できる。その数値範囲は前記範囲が望ましく、この数値より小さければ歪みの拡散のため割れる確率が増大し、大きければ結晶性の悪化のため高品質半導体として利用が困難になる。領域Ｂでは領域Ａで発生した歪みの反作用のため半値全幅が拡がるが、前記数値範囲内であれば半導体などの高品質単結晶基板として実用に差し支えない。 The full width at half maximum of the diamond intrinsic Raman peak in region A is preferably 2.0 cm −1 or more and 3.5 cm −1 or less, and that in region B is preferably 1.6 cm −1 or more and 2.5 cm −1 or less. . The full width at half maximum of the Raman peak is a numerical value reflecting crystallinity, and generally the smaller one indicates that the crystal has better quality. In the region A, the full width at half maximum is expanded as compared with a crystal without strain because of compressive strain. The numerical range is preferably the above range, and if it is smaller than this numerical value, the probability of cracking increases due to strain diffusion, and if it is larger, the crystallinity deteriorates, making it difficult to use as a high-quality semiconductor. In the region B, the full width at half maximum is expanded due to the reaction of the strain generated in the region A. However, as long as it is within the numerical range, it may be practically used as a high-quality single crystal substrate such as a semiconductor.
上記ダイヤモンド単結晶基板は、代表的な方法としてダイヤモンド単結晶種基板からのホモエピタキシャル成長で得られるが、異種種基板からのヘテロエピタキシャル成長で得られたものであってもよく、またそれ以外の気相成長法で得られた単結晶基板であってもよい。ホモエピタキシャル成長の場合、ダイヤモンド単結晶種基板上に気相成長法で単結晶が成長した状態でラマン測定しても、種基板を研磨などで除去した状態での測定でもよい。 The diamond single crystal substrate can be obtained by homoepitaxial growth from a diamond single crystal seed substrate as a typical method, but may be obtained by heteroepitaxial growth from a heterogeneous species substrate, or other gas phase. A single crystal substrate obtained by a growth method may be used. In the case of homoepitaxial growth, Raman measurement may be performed with a single crystal grown on a diamond single crystal seed substrate by vapor phase growth, or measurement may be performed with the seed substrate removed by polishing or the like.
また、本発明のダイヤモンド単結晶基板は、ダイヤモンド単結晶種基板からの気相成長により得られたダイヤモンド単結晶基板であって、励起光の集光スポット径が２μｍの顕微ラマン分光法で、種基板層と気相成長層の界面に顕微焦点を設定して測定したダイヤモンド固有ラマンシフトが、界面の、０％より大きく２５％以下の領域（領域Ｃ）では、歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上−０．２ｃｍ−１未満のシフト量であり、界面の領域Ｃ以外の領域（領域Ｄ）では、歪みのないダイヤモンドの標準ラマンシフト量から−０．２ｃｍ−１以上＋０．２ｃｍ−１以下のシフト量であることを特徴とする。 The diamond single crystal substrate of the present invention is a diamond single crystal substrate obtained by vapor phase growth from a diamond single crystal seed substrate, and is obtained by microscopic Raman spectroscopy with a condensing spot diameter of excitation light of 2 μm. In the region where the intrinsic Raman shift measured by setting a micro focus on the interface between the substrate layer and the vapor phase growth layer is greater than 0% and less than 25% of the interface (region C), the standard Raman shift of undistorted diamond a shift amount of less -1.0Cm -1 or more -0.2Cm -1 from the amount, in the region other than the region C of the interface (region D), -0.2cm standard Raman shift of undistorted diamond - The shift amount is 1 or more and +0.2 cm −1 or less.
本発明者らはダイヤモンドのホモエピタキシャル成長に際し、既述の顕微ラマン分光法を応用し、種基板層と気相成長層の界面に顕微焦点を設定してラマンシフト分布を測定した。その結果、既述の領域Ａの直下界面では、ダイヤモンドの標準ラマンシフト量よりも低波数側にシフトすることがわかり、このシフト量及び領域面積と割れに相関が現れることを確認した。すなわち、前記ラマンシフトの領域Ｃは界面の２５％以下であればよいが好ましくは１０％以下、より好ましくは３％以下が適している。一般的には少なければ少ないほどその後のホモエピタキシャル成長などで割れる確率が低下するが、詳細な研究の結果、この歪み領域Ｃが少なくなりすぎても歪みが局所的に集中するために割れる確率が増大する。すなわち、領域Ｃは測定界面の０．１％以上存在する方が望ましい。この領域Ｃのシフト量は、歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上−０．２ｃｍ−１未満のシフト量であればよいが、好ましくは−０．５ｃｍ−１以上−０．２ｃｍ−１未満が適している。 In the homoepitaxial growth of diamond, the present inventors applied the above-mentioned micro Raman spectroscopy, and set the micro focus at the interface between the seed substrate layer and the vapor phase growth layer, and measured the Raman shift distribution. As a result, it was found that the interface immediately below the region A described above shifted to the lower wave number side than the standard Raman shift amount of diamond, and it was confirmed that there was a correlation between the shift amount, the area of the region, and the crack. That is, the Raman shift region C may be 25% or less of the interface, but is preferably 10% or less, more preferably 3% or less. In general, the smaller the number, the lower the probability of cracking by subsequent homoepitaxial growth. However, as a result of detailed research, even if this strain region C becomes too small, the probability of cracking increases due to local concentration of strain. To do. That is, it is desirable that the region C exists at 0.1% or more of the measurement interface. Shift amount of the region C may be a shift of less than -1.0Cm -1 or more -0.2Cm -1 standard Raman shift of undistorted diamonds, preferably -0.5Cm -1 or Less than −0.2 cm −1 is suitable.
領域Ｃは領域Ａの圧縮歪みの反作用として引っ張り歪みが蓄積されており、最も低波数シフトした量が−１．０ｃｍ−１以下の場合割れる確率が増大する。逆に、この数値が−０．２ｃｍ−１に近いほど歪みは小さく割れる確率が低下するので、この基板を種基板としたホモエピタキシャル成長により、割れのない単結晶厚膜を形成することも可能になる。但し、界面に−０．２ｃｍ−１未満の領域がなくなると、結晶全体の歪みのために割れる確率が増大するので、歪みを緩和するためには−０．２ｃｍ−１未満のシフト量がある領域が結晶界面には必要である。すなわち、本発明では−０．２ｃｍ−１未満のシフト量がある上記指定領域を領域Ｃと定義した。また、領域Ｃ以外の測定領域である領域Ｄは、歪みのないダイヤモンドの標準ラマンシフト量から−０．２ｃｍ−１以上＋０．２ｃｍ−１以下のシフト量であればよい。 In the region C, tensile strain is accumulated as a reaction of the compressive strain in the region A, and the probability of cracking increases when the lowest wave number shift amount is −1.0 cm −1 or less. Conversely, the closer this value is to -0.2 cm -1 , the lower the probability that the strain will break, so it is possible to form a single crystal thick film without cracks by homoepitaxial growth using this substrate as a seed substrate. Become. However, if there is no region less than −0.2 cm −1 at the interface, the probability of cracking increases due to the strain of the entire crystal, so there is a shift amount of less than −0.2 cm −1 in order to alleviate the strain. A region is required at the crystal interface. That is, in the present invention, the designated region having a shift amount less than −0.2 cm −1 is defined as region C. The region D is the measurement region other than the region C may be a shift amount of -0.2Cm -1 or + 0.2 cm -1 or less from the standard Raman shift of diamond without distortion.
前記領域Ａ及びＣは、ラマン分布の測定領域面積で前記比率内に入っていればよいが、望ましくは個々の領域が分散して小面積ずつで存在している方がよい。領域Ａ及びＣが、表面あるいは界面の１領域に集中している場合、同面積で領域が分散している場合に比べて、歪みの集中のために割れやすくなる。 The regions A and C only have to be within the ratio in terms of the measurement region area of the Raman distribution, but it is preferable that the individual regions are dispersed and exist in small areas. When the regions A and C are concentrated on one region of the surface or interface, the regions A and C are more likely to break due to the concentration of strain than when the regions are dispersed in the same area.
本発明のダイヤモンド単結晶基板は前記ラマンシフト分布の条件を満たし、かつダイヤモンド単結晶の差し渡し径が１０ｍｍ以上であれば、大型の単結晶基板として特に光学用途などの応用に有望となる。本発明において差し渡し径とは、ある大きさ、形を持つ単結晶内に引くことのできる最大の直線の長さのことである。 The diamond single crystal substrate of the present invention is promising particularly as an optical application as a large single crystal substrate if the conditions for the Raman shift distribution are satisfied and the diameter of the diamond single crystal is 10 mm or more. In the present invention, the span diameter is the maximum length of a straight line that can be drawn in a single crystal having a certain size and shape.
本発明における、単結晶を合成する気相成長法はマイクロ波プラズマＣＶＤ法、直流プラズマＣＶＤ法など、公知のいずれの成長法も使用できる。これらの成長法でダイヤモンド単結晶基板をホモエピタキシャル成長させる場合は、ダイヤモンド単結晶種基板の表面層をあらかじめ反応性イオンエッチングによりエッチング除去してから単結晶を気相成長させる方が望ましい。気相成長用の単結晶種基板の表面は機械的に研磨済みである方が望ましいが、研磨済みの表面には金属不純物や加工欠陥などの、単結晶気相成長に不都合となる加工変質層が含まれる。成長前の反応性イオンエッチングにより、これらの加工変質層の除去が可能となり、かつ、割れの発生しない程度に歪みの分散した高品質のダイヤモンド単結晶が得られる。 As the vapor phase growth method for synthesizing a single crystal in the present invention, any known growth method such as a microwave plasma CVD method or a direct current plasma CVD method can be used. When the diamond single crystal substrate is homoepitaxially grown by these growth methods, it is preferable to vapor-deposit the single crystal after removing the surface layer of the diamond single crystal seed substrate by reactive ion etching in advance. It is desirable that the surface of the single crystal seed substrate for vapor phase growth be mechanically polished, but the polished surface has a work-affected layer that is inconvenient for single crystal vapor phase growth, such as metal impurities and processing defects. Is included. By reactive ion etching before growth, these work-affected layers can be removed, and a high-quality diamond single crystal in which strain is dispersed to such an extent that cracks do not occur can be obtained.
ここで、反応性イオンエッチングは公知の方法で実施できる。その方式には大別して、真空容器中に対向して配置した電極に高周波電源を接続する容量結合型プラズマ（ＣＣＰ）を利用する方式と、真空容器を取り巻くように配置したコイルに高周波電源を接続する誘導結合型プラズマ（ＩＣＰ）を利用する方式が存在し、両方式を組み合わせた方式も存在するが、本発明にはいずれの方式も利用できる。反応性イオンエッチングにおけるエッチングガスは、酸素とフッ化炭素の混合ガスを用い、エッチング圧力は１．３３Ｐａ以上１３．３Ｐａ以下が望ましい。前記ガス種、圧力を用いることで、高速、かつ平坦に加工変質層のみを除去することができる。また、エッチング厚さは０．５μｍ以上５０μｍ以下、エッチング時の基板温度は８００Ｋ以下、好ましくは６００Ｋ以下が適している。これらの条件でエッチングすることにより、その後の気相成長で得られるダイヤモンド単結晶基板の結晶性が向上する。 Here, the reactive ion etching can be performed by a known method. The method is roughly divided into a method using capacitively coupled plasma (CCP) that connects a high-frequency power source to electrodes arranged opposite to each other in a vacuum vessel, and a high-frequency power source connected to a coil arranged so as to surround the vacuum vessel. There are systems that use inductively coupled plasma (ICP), and there are systems that combine both systems, but either system can be used in the present invention. As the etching gas in reactive ion etching, a mixed gas of oxygen and fluorocarbon is used, and the etching pressure is preferably 1.33 Pa or more and 13.3 Pa or less. By using the gas type and pressure, it is possible to remove only the work-affected layer at high speed and flatly. The etching thickness is 0.5 μm or more and 50 μm or less, and the substrate temperature during etching is 800 K or less, preferably 600 K or less. Etching under these conditions improves the crystallinity of the diamond single crystal substrate obtained by subsequent vapor phase growth.
本発明の顕微ラマン分光測定における励起光源は、レーザーなど公知の光源が利用できるが、測定時の基板表面、あるいは種基板層と成長層界面における集光径は２μｍである必要がある。一般的には光源にガスレーザーあるいは固体レーザーを用いた場合、顕微（対物）倍率１００倍のレンズで上記集光径を実現できる。レンズ以外にも可変ピンホールやスリットなどを組み合わせることで上記集光径を実現できる。励起光の集光照射エネルギー密度は任意の値でよいが、ダイヤモンドが損傷しないエネルギー密度（波長により異なる）で実施する必要がある。光源の波長は紫外から赤外まで任意の波長が利用できるが、種基板層と成長層の界面をラマン分光測定する場合は、成長層側から励起光を入射し、ラマンシフト光を測定する必要があるので、成長層で吸収されない波長を選択する必要がある。本発明で使用するラマン分光装置の波長分解能は、アルゴンレーザーの５１４．５ｎｍ発光におけるレイリー散乱光ピークの半値全幅で２．０ｃｍ−１以下であればよい。本発明のラマンシフトピークの波数及び半値全幅は、ガウスローレンツフィッティングで求められる。ラマンシフトの面分布を測定する場合、測定面を５μｍ以下の格子状に区切り、格子点におけるラマンシフトを測定した上でシフト量を面プロットすることで判定できる。格子間のシフト量は補間で推定できるので、それぞれの領域の面積が求められる。 A known light source such as a laser can be used as the excitation light source in the microscopic Raman spectroscopic measurement of the present invention, but the condensing diameter at the substrate surface or the seed substrate layer / growth layer interface at the time of measurement needs to be 2 μm. In general, when a gas laser or a solid-state laser is used as a light source, the light condensing diameter can be realized with a lens having a microscopic (objective) magnification of 100 times. The condensing diameter can be realized by combining a variable pinhole or slit in addition to the lens. Although the collection energy density of the excitation light may be an arbitrary value, it is necessary to carry out at an energy density (depending on the wavelength) that does not damage the diamond. The wavelength of the light source can be any wavelength from ultraviolet to infrared. However, when performing Raman spectroscopic measurement at the interface between the seed substrate layer and the growth layer, it is necessary to enter the excitation light from the growth layer side and measure the Raman shift light. Therefore, it is necessary to select a wavelength that is not absorbed by the growth layer. The wavelength resolution of the Raman spectroscopic device used in the present invention may be 2.0 cm −1 or less in terms of the full width at half maximum of the Rayleigh scattered light peak in the 514.5 nm emission of an argon laser. The wave number and full width at half maximum of the Raman shift peak of the present invention can be determined by Gaussian Lorentz fitting. When measuring the surface distribution of the Raman shift, it can be determined by dividing the measurement surface into a grid of 5 μm or less, measuring the Raman shift at the lattice points, and then plotting the shift amount in a surface plot. Since the shift amount between the lattices can be estimated by interpolation, the area of each region is obtained.
本発明は割れのないダイヤモンド単結晶基板を提供することができ、大型かつ高品質なダイヤモンド単結晶基板として半導体材料、電子部品、光学部品などに利用可能である。 INDUSTRIAL APPLICABILITY The present invention can provide a diamond single crystal substrate having no cracks, and can be used for a semiconductor material, an electronic component, an optical component, etc. as a large and high quality diamond single crystal substrate.
以下、本発明を実施例に基づき詳細に説明する。 Hereinafter, the present invention will be described in detail based on examples.
本実施例では高温高圧合成法で得られたダイヤモンド単結晶種基板からホモエピタキシャル成長させ、気相成長ダイヤモンド単結晶基板を得た例について述べる。種基板のサイズは縦横８ｍｍ（差し渡し径１１．２ｍｍ）、厚さ０．３ｍｍの立方体で主面・側面は機械的に研磨済みである。主面・側面の面方位はいずれも｛１００｝とした。まず、種基板の主面表面層を、公知の高周波電極間放電型の反応性イオンエッチングによりエッチング除去した。エッチング条件を表１に示す。 In this example, an example of obtaining a vapor phase grown diamond single crystal substrate by homoepitaxial growth from a diamond single crystal seed substrate obtained by a high temperature and high pressure synthesis method will be described. The size of the seed substrate is 8 mm in length and width (passing diameter 11.2 mm) and a cube having a thickness of 0.3 mm, and the main surface and side surfaces are mechanically polished. The surface orientations of the main surface and side surfaces were both {100}. First, the main surface surface layer of the seed substrate was etched away by a known high-frequency inter-electrode discharge type reactive ion etching. The etching conditions are shown in Table 1.
表１
高周波周波数：１３．５６ＭＨｚ
高周波電力：３００Ｗ
チャンバ内圧力：６．６７Ｐａ
Ｏ２ガス流量：１０ｓｃｃｍ
ＣＦ４ガス流量：１０ｓｃｃｍ
基板温度：５５０Ｋ
エッチング時間：１時間
表１の条件によりエッチングしたところ、種基板の主面は０．６μｍエッチング除去された
Table 1
High frequency frequency: 13.56 MHz
High frequency power: 300W
Chamber pressure: 6.67 Pa
O 2 gas flow rate: 10 sccm
CF 4 gas flow rate: 10 sccm
Substrate temperature: 550K
Etching time: 1 hour When etching was performed under the conditions shown in Table 1, the main surface of the seed substrate was removed by 0.6 μm.
次に、種基板上に公知のマイクロ波プラズマＣＶＤ法で単結晶をホモエピタキシャル成長させた。成長条件を表２に示す。
表２
マイクロ波周波数：２．４５ＧＨｚ
マイクロ波電力：５ｋＷ
チャンバ内圧力：１．３３×１０４Ｐａ
Ｈ２ガス流量：１００ｓｃｃｍ
ＣＨ４ガス流量：５ｓｃｃｍ
基板温度：１２００Ｋ
成長時間：２０時間
成長の結果、気相成長単結晶層の厚さが０．１ｍｍのダイヤモンド単結晶基板が得られた。
Next, a single crystal was homoepitaxially grown on the seed substrate by a known microwave plasma CVD method. Table 2 shows the growth conditions.
Table 2
Microwave frequency: 2.45 GHz
Microwave power: 5kW
Chamber pressure: 1.33 × 10 4 Pa
H 2 gas flow rate: 100 sccm
CH 4 gas flow rate: 5 sccm
Substrate temperature: 1200K
Growth time: 20 hours As a result of the growth, a diamond single crystal substrate having a vapor growth single crystal layer thickness of 0.1 mm was obtained.
次に、得られたダイヤモンド単結晶基板の表面、および種基板層と成長層界面について、表３の条件でラマンシフトの面分布測定を行った。
表３
励起光源：ＬＤ励起ＹＡＧレーザー２倍高調波
波長：５３２ｎｍ
集光スポット径：２μｍ
波長分解能：１．６ ｃｍ−１（５３２ｎｍレイリー散乱光において）
集光照射エネルギー：１０ｍＷ
測定点：基板表面、および種基板層／成長層界面、５μｍ間隔格子状
測定の模式図を図１に示す。図１中、１はダイタモンド単結晶基板気相成長層、２はダイタモンド単結晶基板種基板層、３はラマン分光測定（表面測定）用レーザー光源、４はラマン分光測定（種基板／成長界面測定）用レーザー光源であるり、５はラマン分布測定スキャン方向をそれぞれ示す。
Next, the surface distribution of the Raman shift was measured under the conditions shown in Table 3 for the surface of the obtained diamond single crystal substrate and the seed substrate layer / growth layer interface.
Table 3
Excitation light source: LD excitation YAG laser double harmonic Wavelength: 532 nm
Condensing spot diameter: 2 μm
Wavelength resolution: 1.6 cm −1 (in 532 nm Rayleigh scattered light)
Condensing irradiation energy: 10 mW
Measurement points: substrate surface, seed substrate layer / growth layer interface, 5 μm-interval grid pattern A schematic diagram of the measurement is shown in FIG. In FIG. 1, 1 is a diamond single crystal substrate vapor growth layer, 2 is a diamond single crystal substrate seed substrate layer, 3 is a laser light source for Raman spectroscopy (surface measurement), and 4 is a Raman spectroscopy measurement (seed substrate / growth interface measurement). ) Laser light source, and 5 indicates the scanning direction of the Raman distribution measurement.
上記表３の条件で測定した代表的なラマンスペクトル例を図２に示す。図中、６は標準ラマンスペクトル例、７は領域Ａのラマンスペクトル例、８は領域Ｃのラマンスペクトル例を示す。図２に示されるように、成長表面では歪みのないダイヤモンドの標準シフト量である１３３２ｃｍ−１より高波数側にシフトした領域が観測され、逆に種基板層と成長層の界面では１３３２ｃｍ−１より低波数側にシフトした領域が観測された。 A typical Raman spectrum example measured under the conditions in Table 3 is shown in FIG. In the figure, 6 is an example of a standard Raman spectrum, 7 is an example of a Raman spectrum in region A, and 8 is an example of a Raman spectrum in region C. As shown in FIG. 2, a region shifted to a higher wave number side than the standard shift amount of 1332 cm −1 of undistorted diamond is observed on the growth surface, and conversely, 1332 cm −1 at the interface between the seed substrate layer and the growth layer. A region shifted to a lower wavenumber side was observed.
そこで、計測されたラマンシフトピークについてガウスローレンツフィッティングしてピーク波数を求め、標準シフト量からのずれ量分布を求めた。基板表面の一部領域（７０μｍ×７０μｍ）の分布測定例を図３に、種基板層／成長層界面の一部領域（７０μｍ×７０μｍ）の分布を図４に示す。図３に示すように、表面の一部の領域（領域Ａ）ではダイヤモンド標準シフトから＋０．５〜＋０．８ｃｍ−１のシフト量で比較的圧縮歪みが大きく、残る領域（領域Ｂ）は−０．４〜＋０．４ｃｍ−１のシフト量で歪みがほとんどないことがわかった。さらに図４に示すように、界面の一部の領域（領域Ｃ）ではダイヤモンド標準シフトから−０．４〜−０．３ｃｍ−１のシフト量で比較的引っ張り歪みが大きく、残る領域（領域Ｄ）は−０．２〜＋０．２ｃｍ−１のシフト量で歪みがほとんどないこともわかった。この方法で単結晶基板全面を評価し、得られた領域Ａ，Ｂ，Ｃ，Ｄの面積比はそれぞれ０．５％、９５．５％、０．３％、９９．７％であった。さらに、領域Ａのラマンピーク半値全幅は２．１〜２．６ｃｍ−１であり、領域Ｂのそれは１．７〜２．４ｃｍ−１であった。 Thus, the measured Raman shift peak was subjected to Gaussian Rentz fitting to obtain the peak wave number, and the deviation amount distribution from the standard shift amount was obtained. FIG. 3 shows an example of distribution measurement of a partial region (70 μm × 70 μm) on the substrate surface, and FIG. 4 shows a distribution of a partial region (70 μm × 70 μm) at the seed substrate layer / growth layer interface. As shown in FIG. 3, in a partial region (region A) of the surface, the compressive strain is relatively large with a shift amount of +0.5 to +0.8 cm −1 from the standard diamond shift, and the remaining region (region B) is − It was found that there was almost no distortion at a shift amount of 0.4 to +0.4 cm −1 . Further, as shown in FIG. 4, in a partial region (region C) of the interface, the tensile strain is relatively large with a shift amount of −0.4 to −0.3 cm −1 from the standard diamond shift, and the remaining region (region D). It was also found that there was almost no distortion at a shift amount of −0.2 to +0.2 cm −1 . The entire surface of the single crystal substrate was evaluated by this method, and the area ratios of the obtained regions A, B, C, and D were 0.5%, 95.5%, 0.3%, and 99.7%, respectively. Further, the full width at half maximum of the Raman peak in region A was 2.1 to 2.6 cm −1 , and that in region B was 1.7 to 2.4 cm −1 .
次に、前記の方法で得られたダイヤモンド単結晶基板に対し表２と同じ条件で、成長時間を８０時間とした追加のホモエピタキシャル成長を行った。その結果、気相成長単結晶層の厚さは合計０．５ｍｍとなった。ここで、表３と同じ条件でラマンシフトの面分布測定を行った結果、前記と同様のシフト分布が計測された。両者の混同を避けるため新たに計測した領域をそれぞれ（’）付きで表すとすると、領域Ａ’、Ｂ’、Ｃ’、Ｄ’における標準シフト量からのずれ量はそれぞれ＋０．５〜＋１．０ｃｍ−１、−０．５〜＋０．４ｃｍ−１、−０．５〜−０．３ｃｍ−１、−０．２〜＋０．２ｃｍ−１となり、それぞれの面積比は２．９％、９７．１％、１．４％、９８．６％となった。さらに、領域Ａ’のラマンピーク半値全幅は２．４〜３．４ｃｍ−１であり、領域Ｂ’のそれは２．０〜２．５ｃｍ−１であった。前半の成長、計測に比べ、追加成長ではラマンシフトのずれ量（歪み量）、ずれ領域（領域Ａ’、Ｃ’）面積、ピーク半値全幅とも増加したが、単結晶基板として割れずに成長できることがわかった。そして、成長後の単結晶基板について種基板部分を機械的な研磨加工で除去し、光透過スペクトルを測定した結果、結晶全面にわたり２２５ｎｍの吸収端から近赤外まで透過率６０％以上を示し、高品質単結晶であることがわかった。これらの結果、本実施例のダイヤモンド単結晶基板は大型かつ高品質であることを確認した。 Next, additional homoepitaxial growth was carried out on the diamond single crystal substrate obtained by the above method under the same conditions as in Table 2 with a growth time of 80 hours. As a result, the total thickness of the vapor growth single crystal layer was 0.5 mm. Here, as a result of measuring the surface distribution of the Raman shift under the same conditions as in Table 3, the same shift distribution as described above was measured. If newly measured areas are represented with (′) in order to avoid confusion between the two, the deviation amounts from the standard shift amounts in the areas A ′, B ′, C ′, and D ′ are +0.5 to +1. 0 cm −1 , −0.5 to +0.4 cm −1 , −0.5 to −0.3 cm −1 , and −0.2 to +0.2 cm −1 . The respective area ratios are 2.9% and 97 0.1%, 1.4%, and 98.6%. Further, the full width at half maximum of the Raman peak in region A ′ was 2.4 to 3.4 cm −1 , and that in region B ′ was 2.0 to 2.5 cm −1 . Compared to the growth and measurement of the first half, the additional growth has increased the shift amount (strain amount), shift area (region A ′, C ′) area, and full width at half maximum of the peak, but it can grow as a single crystal substrate without cracking. I understood. And as a result of removing the seed substrate portion of the grown single crystal substrate by mechanical polishing and measuring the light transmission spectrum, the transmittance is 60% or more from the absorption edge of 225 nm to the near infrared over the entire crystal surface, It was found to be a high quality single crystal. As a result, it was confirmed that the diamond single crystal substrate of this example was large and high quality.
次に表１におけるエッチング時間を変更した実施例（実施例２）および比較例について述べる。単結晶成長条件および評価項目・条件は先の実施例と同様である。エッチング時間とラマン評価結果について表４に示す。 Next, an example (Example 2) in which the etching time in Table 1 is changed and a comparative example will be described. Single crystal growth conditions and evaluation items / conditions are the same as in the previous examples. Table 4 shows the etching time and the Raman evaluation result.
表４における実施例２は、気相成長前のエッチング時間を短くしたエッチング厚が薄い場合の例である。１回目のホモエピタキシャル成長では、先の実施例に比べて領域Ａ、Ｃが拡がり、ピークずれ、ピーク半値全幅も大きくなったが成長後は割れずに一体であった。しかし、その後の２回目の成長後には単結晶基板は種結晶ごと割れ、初期歪みが拡大した結果割れたことがわかった。割れた基材について、ラマンシフト分布を計測した結果、最大ピークずれ、歪み領域Ａ、Ｃとも１回目より拡大しており、結晶性が悪化していることがわかった。 Example 2 in Table 4 is an example where the etching time before vapor phase growth is shortened and the etching thickness is thin. In the first homoepitaxial growth, the regions A and C were expanded as compared with the previous example, and the peak shift and the full width at half maximum of the peak were increased, but after the growth, they were integrated without cracking. However, after the second growth, the single crystal substrate cracked together with the seed crystal, and it was found that the initial strain was enlarged and cracked. As a result of measuring the Raman shift distribution for the cracked substrate, it was found that both the maximum peak deviation and the strain regions A and C were enlarged from the first time, and the crystallinity was deteriorated.
参考例は気相成長前のエッチング時間を長くしたエッチング厚が厚い場合の例である。１回目のホモエピタキシャル成長では実施例２とは逆に領域Ａ、Ｃが狭まり、ほとんど観測されなかったが、その後の２回目の成長では逆に領域、シフトずれとも拡がり、その結果基板が割れた。すなわち、初期歪みが少なすぎても割れ防止の観点からは問題があることがわかった。
これらの結果から、初期のエッチング厚さの差によって割れのないホモエピタキシャル成長のできる厚さが限定され、その歪み量しきい値を前記ラマン測定法で特定できることがわかった。また、逆に成長後のラマンシフト量・分布の測定により、その後の追加成長時に割れが生じる可能性を予測することが可能になった。
The reference example is an example in which the etching thickness is increased by increasing the etching time before vapor phase growth. In the first homoepitaxial growth, the regions A and C were narrowed in contrast to Example 2, and almost no observation was observed. However, in the subsequent second growth, both the region and the shift deviation were expanded, and as a result, the substrate was cracked. That is, it has been found that there is a problem from the viewpoint of preventing cracking even if the initial strain is too small.
From these results, it was found that the thickness at which homoepitaxial growth without cracking is limited by the difference in the initial etching thickness, and the threshold value of the strain amount can be specified by the Raman measurement method. On the other hand, by measuring the amount and distribution of Raman shift after growth, it became possible to predict the possibility of cracking during subsequent additional growth.
最後に、気相成長前のエッチングを行わなかった比較例では、１回目のホモエピタキシャル成長後に基板が割れた。割れた基材のラマンシフト分布を計測した結果、歪み領域Ａ、Ｃの面積、ピークずれ、ピーク半値全幅とも実施例２より拡大し、１回目の成長で割れしきい値を超えたために割れたことがわかった。 Finally, in the comparative example in which the etching before vapor phase growth was not performed, the substrate was cracked after the first homoepitaxial growth. As a result of measuring the Raman shift distribution of the cracked substrate, the area of the strain regions A and C, the peak shift, and the full width at half maximum of the peak were expanded from those in Example 2 and cracked because the crack growth threshold was exceeded in the first growth. I understood it.
これらの結果から、実施例に代表されるダイヤモンド単結晶は、半導体や光学部品に利用できる大型かつ高品質な単結晶基板であることが示された。 From these results, it was shown that the diamond single crystal represented by the Examples is a large-sized and high-quality single crystal substrate that can be used for semiconductors and optical components.
１ ダイヤモンド単結晶基板気相成長層
２ ダイヤモンド単結晶基板種基板層
３ ラマン分光測定（表面測定）用レーザー光源
４ ラマン分光測定（種基板／成長界面測定）用レーザー光源
５ ラマン分布測定スキャン方向
６ 標準ラマンスペクトル例
７ 領域Ａのラマンスペクトル例
８ 領域Ｃのラマンスペクトル例
1 Diamond single crystal substrate vapor
Claims (3)
励起光の集光スポット径が２μｍの顕微ラマン分光法で測定した、ダイヤモンド単結晶基板表面のダイヤモンド固有ラマンシフトが、
表面の０．１％以上１０％以下の領域（領域Ａ）では、歪みのないダイヤモンドの標準ラマンシフト量から＋０．５ｃｍ−１以上＋３．０ｃｍ−１以下のシフト量であり、
表面の領域Ａ以外の領域（領域Ｂ）では、歪みのないダイヤモンドの標準ラマンシフト量から−１．０ｃｍ−１以上＋０．５ｃｍ−１未満のシフト量であることを特徴とする、
ダイヤモンド単結晶基板。 A diamond single crystal substrate obtained by vapor deposition,
The diamond-specific Raman shift on the surface of the diamond single crystal substrate, measured by microscopic Raman spectroscopy with a condensing spot diameter of the excitation light of 2 μm,
In the region of 0.1% or more and 10 % or less of the surface (region A), the shift amount is from +0.5 cm −1 or more to +3.0 cm −1 or less from the standard Raman shift amount of diamond without distortion,
In the surface of the region A than in region (region B), characterized in that it is a shift amount of less -1.0Cm -1 or + 0.5 cm -1 from the standard Raman shift of undistorted diamond,
Diamond single crystal substrate.
領域Ｂのダイヤモンド固有ラマンピークの半値全幅が１．６ｃｍ−１以上２．５ｃｍ−１以下であることを特徴とする、
請求項１に記載のダイヤモンド単結晶基板。 The full width at half maximum of the diamond intrinsic Raman peak in region A is 2.0 cm −1 or more and 3.5 cm −1 or less,
The full width at half maximum of the diamond intrinsic Raman peak in region B is 1.6 cm −1 or more and 2.5 cm −1 or less,
The diamond single crystal substrate according to claim 1 .
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004085930A JP4736338B2 (en) | 2004-03-24 | 2004-03-24 | Diamond single crystal substrate |
| EP05250803A EP1591565A1 (en) | 2004-03-24 | 2005-02-11 | Diamond single crystal substrate |
| US11/055,973 US7955434B2 (en) | 2004-03-24 | 2005-02-14 | Diamond single crystal substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004085930A JP4736338B2 (en) | 2004-03-24 | 2004-03-24 | Diamond single crystal substrate |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009183178A Division JP5152124B2 (en) | 2009-08-06 | 2009-08-06 | Diamond single crystal substrate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005272191A JP2005272191A (en) | 2005-10-06 |
| JP4736338B2 true JP4736338B2 (en) | 2011-07-27 |
Family
ID=34940460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004085930A Expired - Lifetime JP4736338B2 (en) | 2004-03-24 | 2004-03-24 | Diamond single crystal substrate |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US7955434B2 (en) |
| EP (1) | EP1591565A1 (en) |
| JP (1) | JP4736338B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2549283A1 (en) * | 2004-11-05 | 2006-05-11 | Sumitomo Electric Industries, Ltd. | Single-crystal diamond |
| JP5002982B2 (en) | 2005-04-15 | 2012-08-15 | 住友電気工業株式会社 | Method for producing single crystal diamond |
| GB201704128D0 (en) * | 2017-03-15 | 2017-04-26 | Univ Swansea | Method and apparatus for use in diagnosis and monitoring of colorectal cancer |
| KR102655136B1 (en) * | 2017-10-20 | 2024-04-04 | 스미토모덴키고교가부시키가이샤 | synthetic single crystal diamond |
| CN112160023A (en) * | 2020-10-09 | 2021-01-01 | 西安奕斯伟硅片技术有限公司 | Method and system for centering seed crystal rotating rod and crucible rotating base |
| JP7561174B2 (en) | 2022-12-17 | 2024-10-03 | エレメント シックス リミテッド | Diamond abrasive grains for use in grinding wheels for semiconductor components, and method for manufacturing diamond abrasive grains for use in grinding wheels for semiconductor components |
| WO2024127679A1 (en) | 2022-12-17 | 2024-06-20 | 株式会社ディスコ | Grinding stone for processing semiconductor member, tool for processing semiconductor member, semiconductor production device, and method for producing grinding stone for processing semiconductor member |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003277183A (en) * | 2002-03-22 | 2003-10-02 | Sumitomo Electric Ind Ltd | Method for producing diamond single crystal, diamond single crystal substrate, and method for producing the same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5127983A (en) | 1989-05-22 | 1992-07-07 | Sumitomo Electric Industries, Ltd. | Method of producing single crystal of high-pressure phase material |
| JPH0585892A (en) * | 1991-07-31 | 1993-04-06 | Nec Corp | Diamond thin film and its production |
| US5614019A (en) * | 1992-06-08 | 1997-03-25 | Air Products And Chemicals, Inc. | Method for the growth of industrial crystals |
| JP3387154B2 (en) * | 1993-06-30 | 2003-03-17 | 住友電気工業株式会社 | Diamond single crystal |
| JPH06227895A (en) * | 1993-02-04 | 1994-08-16 | Sumitomo Electric Ind Ltd | Synthesis of diamond |
| US7481879B2 (en) * | 2004-01-16 | 2009-01-27 | Sumitomo Electric Industries, Ltd. | Diamond single crystal substrate manufacturing method and diamond single crystal substrate |
-
2004
- 2004-03-24 JP JP2004085930A patent/JP4736338B2/en not_active Expired - Lifetime
-
2005
- 2005-02-11 EP EP05250803A patent/EP1591565A1/en not_active Ceased
- 2005-02-14 US US11/055,973 patent/US7955434B2/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003277183A (en) * | 2002-03-22 | 2003-10-02 | Sumitomo Electric Ind Ltd | Method for producing diamond single crystal, diamond single crystal substrate, and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2005272191A (en) | 2005-10-06 |
| EP1591565A1 (en) | 2005-11-02 |
| US7955434B2 (en) | 2011-06-07 |
| US20050211159A1 (en) | 2005-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7771693B2 (en) | Diamond single crystal substrate manufacturing method | |
| JP4613314B2 (en) | Single crystal manufacturing method | |
| JP5002982B2 (en) | Method for producing single crystal diamond | |
| EP1832672B1 (en) | Single-crystal diamond | |
| JP4374823B2 (en) | Method for producing diamond single crystal and method for producing diamond single crystal substrate | |
| JP5794334B2 (en) | Method for producing single crystal diamond | |
| US7955434B2 (en) | Diamond single crystal substrate | |
| TW201829857A (en) | Foundation substrate for producing diamond film and method for producing diamond substrate using same | |
| KR100358314B1 (en) | A Rigid Carbon Film and A Substrate for Surface Acoustic Wave Device Coated Therewith | |
| WO2016013588A1 (en) | Single-crystal diamond and method for manufacturing same, tool including single-crystal diamond, and component including single-crystal diamond | |
| KR20210060357A (en) | Diamond substrate and preparing method thereof | |
| JP4294140B2 (en) | Diamond thin film modification method, diamond thin film modification and thin film formation method, and diamond thin film processing method | |
| KR102653291B1 (en) | Single crystal diamond, method for producing single crystal diamond, and chemical vapor deposition device used therefor | |
| JP5152124B2 (en) | Diamond single crystal substrate | |
| JP4697514B2 (en) | Diamond single crystal substrate manufacturing method and diamond single crystal substrate | |
| JP4525897B2 (en) | Diamond single crystal substrate | |
| JP4375495B2 (en) | Diamond single crystal substrate and method for producing diamond single crystal | |
| EP4357492A1 (en) | Diamond substrate and manufacturing method for same | |
| JPWO2019059123A1 (en) | Single crystal diamond and its manufacturing method | |
| JP5042134B2 (en) | Diamond thin film | |
| Malakhov | Growth and optical investigations of InN textured layers | |
| JP2007204307A (en) | Method for synthesizing diamond |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070302 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20090604 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090617 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090804 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100514 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100701 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20101118 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110125 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20110201 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20110405 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20110418 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4736338 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140513 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |